The invention relates to an aluminum alloy material exhibiting excellent bendability, and a method for producing the same.
A high-strength aluminum alloy has been widely used for transportation machines such as motorcycles in order to implement a reduction in weight. In particular, 2000 series aluminum alloys (e.g., 2017 alloy and 2024 alloy) have been widely applied to structural members due to excellent fatigue strength. These aluminum alloys are normally used as a T3-tempered material, a T4-tempered material, a T6-tempered material, a T8-tempered material, or the like.
An aluminum alloy material used for structural members of transportation machines may be subjected to bending depending on the application. However, when a T3-tempered material, a T4-tempered material, a T6-tempered material, a T8-tempered material, or the like formed of a 2000 series aluminum alloy is subjected to bending, cracks may occur during bending due to too high a strength, or a change in shape may occur due to a large amount of spring-back.
Therefore, a 2000 series aluminum alloy is normally O-tempered, bent, and then subjected to a solution treatment and quenching to prepare a T3-tempered material, a T4-tempered material, a T6-tempered material, a T8-tempered material, or the like. However, since deformation occurs during quenching, it is necessary to perform straightening (i.e., an increase in cost occurs). Therefore, a reduction in cost through omission of straightening has been desired.
For example, a reduction in cost through omission of straightening has been desired for a T4-tempered material formed of a 2024 alloy that is used to form an extruded pipe and subjected to bending. Since an extruded pipe formed of a 2024 alloy has a configuration in which the inner part of the material has a fiber structure (texture) and the surface area of the material has a coarse recrystallized structure, orange peel may occur during bending, and the external appearance may deteriorate. Therefore, it has been desired to suppress the occurrence of orange peel during bending by controlling the structure.
JP-A-4-000353 discloses related-art technology.